Propane gas torches are well known and disclosed in a number of patents. Examples of known gas torches are disclosed in U.S. Pat. Nos. 3,663,154 (J. K. Locke), 3,768,962 (F. Baranowski, Jr.) and 4,013,395 (A. F. Wormser). Each of these gas torches is provided with a venturi for introducing air into the combustible mixture; the use of a venturi adds to the cost of manufacture and assembly. Also, these torches are not provided with internal igniters.
Patented gas torches which are provided with spark igniters, but are also provided with a venturi, are exemplified by U.S. Pat. Nos. 4,348,172 (H. C. Miller) and 4,526,532 (J. M. Nelson).
An example of a prior art gas torch which does not require a venturi, but also is not provided with a built-in igniter, is exemplified by U.S. Pat. No. 3,806,038 (J. M. Nelson).